1. Field of the Invention
The present invention pertains to a rotary bit driving and backforce accommodating assembly configured as an attachment for an electrical conductor wrapping tool.
2. Background
In the art of conductor wrapping tools wherein flexible electrical conductor wires are coiled in a series of helical convolutions about a terminal pin by a rotary bit it is desirable to provide an arrangement wherein the bit is allowed to undergo axial excursion away from the wire coils as the successive helical convolutions are formed to prevent excessive coiling forces and to actually physically accommodate the growth in axial length of the coil. In this regard it has been proposed as described, for example, in U.S. Pat. No. 3,480,119 to provide bit driving structure wherein a bit driver member is mounted for axial movement with the bit away from the wire coil as it is being formed against the urging of a spring member or the like wherein the bit is constantly urged in the working position but is allowed to undergo axial excursion relative to the driving tool. In this way the operator does not have to accommodate the growth in axial length of the wire coil during the coiling process.
One problem associated with prior art types of conductor coiling or wrapping tools is that the sizing of the spring for urging the bit in the working position may be suitable for one particular wire gauge or size but is then often unsuitable for larger or smaller wire sizes or for connections having a large number of helical convolutions. Prior art practice to overcome this problem has resulted in the need to provide several different tools at the operator work station for use with the specific sizes of conductor wires being coiled by the operator. The provision of plural tools has been necessitated by prior art designs in view of the fact that access to the tool working parts to interchange springs which provide the backforce counteracting force is difficult. However, it is important that a conductor wrapping tool of the general type described herein be provided with means for use with various wire sizes which will accommodate the backforce exerted on the conductor wrapping bit to prevent damage to the wire coils or the bit camming face for a relatively wide range of wire sizes. In this regard the present invention has been developed with a view to overcoming the deficiencies of prior art conductor wrapping tools.